In typical operation, a personal computer supports a single keyboard and a single pointing device. A number of software tools have been developed, however, to allow more than one pointing device to be used in computer applications, particularly for multi-player games. Examples include CPNMouse, which is available at SourceForge.net, and ManyMouse, available at icculus.org.
Remote desktop programs enable the user of one computer to view the desktop of another computer and control the functions of that computer remotely (via the Internet or other network). Some remote desktop tools permit a computer to be controlled simultaneously by a remote user and a local user. Such tools may, for example, permit both the local and remote users to move a cursor on the local user's computer screen by manipulating their respective pointing devices, or to enter text via their respective keyboards.
Whereas many tools give the remote user full control over all computer operations, methods have been proposed for limiting the scope of remote control. For example, U.S. Pat. No. 5,758,110, whose disclosure is incorporated herein by reference, describes a method for task-based application sharing, in which a host user designates an application to be shared with another user at a remote location, referred to as the client user. The shared application runs and executes only on the host system. The client system renders an image of all windows of the shared application without also displaying unshared applications. Both the client and the host users continue to perform normal operations outside of the shared area, and the host user defines the tasks which are to be shared.